The present invention relates to technology concerning the production of IC cards, and, more particularly, to technology which is applicable effectively to the process of IC card production, including reliable and general testing steps adapted to a variety of IC cards.
In the technology which the inventors of the present invention have studied, there is for example an IC (Integrated Circuit) card, which has the same shape as cards with magnetic stripes, represented by credit cards and cashless cards for banking, which are widely used in the current society, and in which a CPU (Central Processing Unit) and memory are incorporated. The use of IC cards is expected to grow in the future, particularly as a portable information recording medium utilizing the most advanced technology of the high-level information society. Such an IC card is capable of exchanging information with an external device through contact terminals or a non-contact antenna coil while being controlled by a control program which is run by the CPU. The built-in memory is controlled so that it is accessible only in response to operation in accordance with a certain procedure for effecting complete security.
The IC card has a variety of functions, and, therefore, its pre-shipment testing is crucial. The testing scheme for the IC card is described for example in the publication of ISO/IEC 7816-3, IC cards and IC cards with external terminals, Part 3: electrical signals and transmission protocol. This publication suggests a IC card data writing test using a tester, for example, in which the tester sends a write command to the IC card and the IC card acknowledges the end of writing to the tester. On completion of several items of test based on the response to the transmitted commands, IC cards excluding faulty ones are shipped.
A study on the testing scheme for the IC card conducted by the inventors of the present invention has revealed the following concerns.
(1) Among a variety of IC cards having extensive fields of application, IC cards used in specific fields, such as banking, are required to be highly reliable in regard to the storage area of the internal memory and also in regard to information stored in the storage area.
(2) A variety of IC cards having extensive fields of application are required to be general so as to be adaptive to the testing with testers and the read/write operation with reader/writers.
With regard to the reliability of the storage area of an IC card memory and information in the storage area, it is an object of the present invention to provide a method of producing IC cards, including testing steps which can particularly improve the reliability of the IC cards.
With regard to the generality of IC cards so as to be adaptive to various testers and reader/writers, it is another object of the present invention to provide a method of producing IC cards, including testing steps which can particularly improve the generality of the IC cards.
These and other objects and novel features of the present invention will become apparent from the following description in this specification taken in conjunction with the accompanying drawings.
Among the aspects of the present invention disclosed in this specification, representative features are summarized as follows.
An IC card producing method based on this invention includes testing adapted to a variety of IC cards, and specifically it includes a chip testing step which implements an electrical characteristic test for the chip in the form of a semiconductor wafer or a separated chip, and an IC card testing step which implements an electrical characteristic test for the IC card in its state having a tested chip.
Another IC card producing method based on this invention includes the electrical characteristic testing of an IC card, and specifically it includes an operational testing step tor the IC card internal circuit based on external test data and a verification step for the IC card internal memory.
Particularly, the operational testing step for the IC card internal circuit is designed to obtain a comparison within the IC card between write-in data and read-out data of the internal memory, such as an EEPROM, and take out only the result of comparison, i.e., agreement or disagreement, from the IC card, with data writing being retried in the case of a disagreement comparison result.
In consequence, this IC card producing method, with the chip testing steps and the IC card testing steps for the IC card in a state having a tested chip being applied thereto, can enhance the reliability of the IC cards. Specifically, although the IC parts of the memory have been tested by the IC manufacturer, instead of skipping the testing of the IC card with the chip thereon, the card test is conducted again purposely for the sake of enhanced reliability of the IC cards. Moreover, the memory verification test is conducted concurrently with the testing by the tester for the implementation of a dual testing scheme for the IC cards.
By taking out only the result of data comparison which is implemented within the IC card, the security is maintained, while the generality of the IC card can be improved. Although the write/read data comparing function for the memory is not a requisite for the IC card, it is considered to be useful for the IC card tester and reader/writer to gain a desired versatility for treating various IC cards.
The effectiveness achieved by the representative aspects of the invention disclosed in this specification will be summarized as follows.
(1) The IC card producing method, with the testing scheme including a chip testing step for implementing a electrical characteristic test for the chip and an IC card testing step for implementing an electrical characteristic test for the IC card in its state having a tested chip being applied thereto, can enhance the reliability of the IC cards.
(2) The IC card testing step, with the IC card dual testing scheme including an operational test of the IC card internal circuit based on external test data and a verification test of the internal memory of IC card being applied thereto, can enhance the reliability of the IC card internal memory.
(3) The operational testing step for the IC card internal circuit, in which write-in data and read-out data of the internal memory are compared within the IC card and only the result of comparison, i.e., agreement or disagreement, is taken out of the IC card, can maintain the security and improve the generality of the IC cards.
(4) The IC card producing method, which ranges from the semiconductor wafer processing step up to the chip on-card mounting step based on the foregoing items (1) through (3), can provide IC card production technology inclusive of highly reliable and general testing step s which are adapted to a variety of IC cards.